Method 1 – Remove Data by Using Available Options:
To remove WP Statistics, you can use the standard WordPress tools. However, removing the plugin will NOT delete the statistical data or settings from the database completely. To remove the tables, data, and settings by going through the Statistics -> Optimization -> Purging tab, and you can empty all tables or delete anything you want using the available options.
You can then go to the WordPress plugins page and disable/delete the plugin from your site.
Method 2 – Delete Data by a Query:
WP Statistics keeps the data in its tables which mean you only need to delete these tables wp_statistics_*
Then don’t forget to delete the plugin’s options with this query.
DELETE FROM wp_options WHERE option_name LIKE '%statistics%'
Please make sure the plugin is disabled before deleting any table.